This invention relates to a surgical instrument and, in one example, a combined laparoscopic scissors and forceps device.
Laparoscopic surgery is used to provide a wide variety of surgical procedures on a patient""s abdomen. The application of laparoscopic methods continues to grow as techniques are refined and the associated surgical instruments are improved. Patients benefit from laparoscopic procedures because the methods employed minimize the amount of trauma associated with a given procedure. Hence, patient survival is enhanced and recovery times are decreased.
Prior art laparoscopic surgical instruments typically include a handle, a 33 centimeter length, 5 millimeter diameter shaft which can be inserted through a cannula placed in a patient""s abdominal wall, and scissors or tissue grasping jaws (e.g., forceps) extending from the end of the shaft.
In some cases, laparoscopic graspers, and/or scissors and some other types of instruments have the ability to apply RF energy in order to locally vaporize tissue and thereby cut through it or to coagulate blood vessels. There are two common ways in which the RF energy is applied. In either method, current travels between two electrodes. In monopolar instruments, the surgical instrument serves as one electrode and the second electrode is a large surface area electrode placed on the patient. In bipolar instruments, both electrodes are disposed on the surgical instrument in close proximity to one another.
Many conventional laparoscopic surgical instruments tend to be clumsier than those used in conventional surgery. As explained above, in laparoscopic surgery, the surgical instruments are inserted through a cannula placed in the patient""s abdominal wall. To keep patient trauma to a minimum, only a limited number of cannula are employed for a given procedure. Often, using existing surgical instruments, the instruments must be repeatedly removed from the cannula and replaced with different instruments and removed and replaced again. This process of repeated instrument exchanges greatly increases the time it takes to perform a given medical procedure.
Two commonly used laparoscopic instruments are scissors and tissue graspers. Scissors are used to dissect tissue, transect ligated vessels or other bodily ducts (such as fallopian tubes), trim sutures and ligatures and to perform other cutting functions. Graspers or forceps are used to coagulate and to grip and manipulate tissue and also to perform a variety of blunt dissecting procedures. Tissue is either grasped and pulled away from substrate tissue to which it is loosely connected or the blunt tips of the closed graspers are inserted between loosely connected tissue strata and then the tips are forced apart separating the tissue strata. The operation of ordinary scissors and forceps is very familiar to surgeons and non-medical personnel alike and their function and operation are somewhat intuitive. This fact remains true when scissors or forceps are incorporated into a traditional laparoscopic instrument.
Traditionally, when tissue cutting procedures are required, a scissors type laparoscopic instrument is used, and, when tissue grasping procedures are required, a forceps type laparoscopic instrument is used. Thus, the surgeon must either employ two cannulas or switch instruments depending on whether cutting or grasping procedures are required.
To overcome this problem, those skilled in the art have developed surgical instruments with detachable scissors and forceps end assemblies, and surgical instruments with combined scissors and forceps end assemblies.
For example, U.S. Pat. No. 5,893,875 discloses a surgical instrument with replaceable end effector assemblies. To switch between tissue cutting and grasping procedures, however, the surgeon must withdraw the instrument from the patient and replace the scissors end effector assembly with a forceps end effector assembly. This practice of instrument exchange greatly increases the time it takes to complete a given surgical procedure.
An attempt to overcome this problem is disclosed by a combined cutting blade/forceps end assembly. See U.S. Pat. Nos. 5,456,684 and 5,908,420. In another prior art device, a cutting blade is extendable between two forceps. See U.S. Pat. Nos. 5,496,317 and 5,573,535. See also the BiCoag(copyright) bipolar cutting forceps available from Everest Medical, 13755 First Avenue North, Minneapolis, Minn. 55441-5454.
All of these devices suffer from the fact that the scissoring and grasping capabilities are poorer than that which is available separately in single function devices.
Moreover, surgeons will not generally use any surgical instrument which does not operate in the way expected or in a way which is not intuitive. When conventional surgical devices with scissor grips are used, it is expected that the action of closing the scissor grips closes the scissor blades for tissue cutting or brings the forceps jaws together to grasp the tissue between them. This is not the case with the devices discussed above. For example, in order to use the device disclosed in U.S. Pat. No. 5,573,535, the surgeon uses a scissor grip to operate the forceps jaws but must operate a separate lever to effect distal movement of the blade member to cut tissue. See the ""535 patent, col. 5, lines 43-66.
Other shortcomings of prior art devices include their complexity and high manufacturing costs. High manufacturing costs are especially important in surgical devices because they are often used in connection with one procedure on a given patient and then discarded.
Still another problem associated with the prior art is the non-ergonomic nature of the handle assembly associated with certain prior art surgical instruments. Surgeons are reluctant to use any surgical instrument whose operation is not fairly self-evident, or is complex, and/or is not similar to the operation of previously used surgical instruments. Also, surgeons desire a surgical instrument which provides feedbackxe2x80x94a positive indication that it is working as intended.
In one prior art example, U.S. Pat. No. 5,403,322, incorporated herein by this reference, discloses a tissue approximator having two pivoting tissue grasping jaws each of which close about a central plate. The handle assembly of this device includes left and right pivoting triggers: the left trigger operates one tissue grasping jaw and the right trigger operates the other tissue grasping jaw.
The structure of this handle assembly is completely different from typical prior art laparoscopic instruments which typically include a scissor type handle with a pivoting trigger spaced from a fixed trigger. Surgeons, however, familiar with scissor type handle assemblies, are reluctant to use laparoscopic instruments with non-scissor type handles.
It is therefore an object of this invention to provide a surgical instrument which operates in the way expected and the use of which is intuitive.
It is a further object of this invention to provide such a surgical instrument which does not require the surgeon to operate separate levers in order to effect tissue cutting or tissue grasping procedures.
It is a further object of this invention to provide a surgical instrument with a handle assembly whose operation is self-evident, simple, and similar to the operation of previously used surgical instruments.
It is a further object of this invention to provide such a surgical instrument a handle assembly which provides a positive indication that it is operating as intended.
It is a further object of this invention to provide such a surgical instrument handle assembly which, in one embodiment, comprises an end effector assembly with a pivoting scissor blade and a pivoting tissue grasping jaw, which locks the scissor blade closed when the tissue grasping jaw is operated and, conversely, which locks the tissue grasping jaw closed when the scissor blade is operated.
It is a further object of this invention to provide such a surgical instrument in which although the tissue grasping jaw is locked closed when the scissor blade is operated, any tissue between the locked closed tissue grasping jaw can escape therefrom if the laparoscopic instrument is moved.
It is a further object of this invention to provide such a surgical instrument which is designed to allow operation of the switching mechanism independent of the drive mechanism so a surgeon can switch between the various modes of operation independent of the position of the pivoting jaws.
It is a further object of this invention to provide a surgical instrument with an end effector assembly which may include a pivoting scissor blade and a pivoting forceps jaw and also other types of surgical end effector assemblies.
It is a further object of this invention to provide such a surgical instrument which eliminates the need for the surgeon to switch instruments during a given medical procedure.
It is a further object of this invention to provide such a surgical instrument which eliminates the need for additional cannulas inserted through a patient""s abdominal wall.
It is a further object of this invention to provide such a surgical instrument in which the scissoring and the grasping capabilities are as good as that which is available separately in single function devices.
It is a further object of this invention to provide such a surgical instrument which is simple in design and which can be manufactured at a low cost.
It is a further object of this invention to provide such a surgical instrument which allows surgeons to remain focused on the operating procedure and not distracted by instrument exchanges or the need to operate separate levers.
It is a further object of this invention to provide such a surgical instrument which results in medical procedures performed in a shorter period of time.
It is a further object of this invention to provide such a surgical instrument which can be accommodated by a five millimeter cannula.
It is a further object of this invention to provide such a surgical instrument which can be easily and ergonomically operated by one hand.
It is a further object of this invention to provide such a surgical instrument which can be equipped with bipolar or monopolar RF energy subsystems for electrosurgical procedures.
It is a further object of this invention to provide such a surgical instrument which can be readily equipped with surgical end effector assemblies other than scissors and tissue graspers.
It is a further object of this invention to provide a surgical instrument with an end effector assembly that may be rotated relative to its handle.
This invention results from the realization that a more intuitive, ergonomic, easier to use, and easier to manufacture surgical instrument which performs, in one example, both tissue cutting and grasping procedures without the need to replace the end effector assembly and which incorporates both scissors and forceps (or other end effector combinations) jaws in a single end effector assembly can be effected by a uniquely configured end effector assembly with a fixed central member that functions both as a scissor blade and a forcep jaw disposed between a separate pivotable scissor blade and a separate pivotable forcep jaw and by a linkage assembly connected between the end assembly and a pair of scissors grips which allows the surgeon to operate the scissor blade when the switching mechanism is in a first position and which allows the surgeon to operate the tissue grasping jaw is when the switching mechanism is in a second position. Moreover, the switching mechanism automatically locks the pivoting scissor blade closed when the tissue grasping jaw is being used and, conversely, the switching mechanism automatically locks the pivoting tissue grasping jaw closed when the pivoting scissor blade is being used. In addition, the switching mechanism can be placed in either the first or second position independent of the position of either the pivoting scissor blade or the pivoting tissue grasping jaw. The result is an ergonomic, easy to use, multi-function laparoscopic instrument which provides positive feedback to the surgeon regarding whether the pivoting tissue grasping jaw is operable or, instead, the pivoting scissor blade is operable.
This invention features a multi-function surgical instrument (e.g., a laparoscopic) comprising an end effector assembly including at least first and second movable members, a first actuator coupled to the first movable member, a second actuator coupled to the second movable member, and a handle assembly. In the preferred embodiment, the handle assembly includes a drive mechanism and a switching mechanism coupled to the drive mechanism. The switching mechanism has at least two positions: a first position in which the drive mechanism is engaged with the first actuator to operate the first movable member and a second position in which the drive mechanism is engaged with the second actuator to operate the second movable member.
Typically, the handle assembly further includes at least one movable trigger pivotably coupled to the drive mechanism. The end effector assembly may include a stationary member between the first and second movable members. In one embodiment, the stationary member has a cutting blade surface and a tissue grasping surface and the first movable member includes a cutting blade surface which cooperates with the cutting blade surface of the stationary member. The second movable member then includes a tissue grasping surface which cooperates with the grasping surface of the stationary member. In one example, the first and second actuators are lengthy rods extending between the end effector assembly and the handle assembly for laparoscopic procedures. A sheath may surround the lengthy rods.
In the preferred embodiment, a first coupler is disposed on the proximal end of the first actuator and a second coupler is disposed on the proximal end of the second actuator. Both couplers are configured to be engaged by the drive mechanism. The first and second couplers each typically include a circumferential groove therein which is engageable by the drive mechanism independent of the rotational orientation of the first and second couplers. The first coupler may also include a passageway which slidably receives the second actuator therethrough and thus the second coupler is positioned rearward of the first coupler in the handle assembly.
The drive mechanism may include a forward clamp engageable with the first coupler and a rearward clamp engageable with the second coupler. In this design, the first coupler includes spaced bushings on opposite sides of the circumferential groove and the forward clamp of the drive mechanism includes a fork-like construction with an opening which receives the circumferential groove of the first coupler therein when the drive mechanism is pivoted to engage the first coupler. Similarly, the second coupler typically includes spaced bushings on opposite sides of the circumferential groove and the rearward clamp of the drive mechanism then includes a fork-like construction with an opening which receives the circumferential groove of the second coupler therein when the drive mechanism is pivoted to engage the second coupler. The handle assembly may further include a stationary trigger spaced forward from the movable trigger.
In the preferred embodiment, the switching mechanism includes at least a first button and a rocking member pivotable between a first position which urges the drive mechanism to engage the first actuator and a second position which urges the drive mechanism to engage the second actuator. The rocking member may include a first locking member which engages the first actuator when the drive mechanism is engaged with the second actuator and a second locking member which engages the second actuator when the drive mechanism is engaged with the first actuator. In one example, the rocking member includes an arm and the switching mechanism further includes a first spring disposed between the first button and the arm of the rocking member which urges the arm in a first direction when the first button is depressed. The first button may also include a pawl which pulls the arm forward when the first button moves from a depressed position to an outward position. In this preferred embodiment, the switching mechanism further includes a second spring which biases the first button in the outward position to urge the arm of the rocking member in a second direction when the first button is released. The switching mechanism may further include a catch which holds the first button in the depressed position and a second button which, when depressed, releases the catch and the first button. The second button is typically biased outward.
It is preferred that the switching mechanism further includes a lock-out subsystem configured to engage the first actuator when the drive mechanism engages the second actuator and to engage the second actuator when the drives mechanism engages the first actuator. Also, a voltage supply lead may be included and electrically connected to one of the first and second movable members for coagulating tissue. The voltage supply lead may be attached to the first actuator and insulation provided to surround the first actuator. A second voltage supply lead may be attached to the second actuator.
The preferred switching mechanism includes a pivotable rocker assembly including a depending arm and forward and rearward shelves which alternately engage the drive mechanism. An actuator is coupled to the depending arm of the rocker assembly. The actuator may be a button including a spring which is disposed to push on the arm of the rocker assembly when the button is depressed, the button further including a pawl biased to pull the arm of the rocker assembly when the button is released. In the preferred embodiment, the pivotable rocker assembly further includes forward and rearward stops disposed to engage whichever actuator is not engaged by the drive mechanism.
This invention further features a multi-function laparoscopic instrument comprising an end effector assembly including at least first and second movable jaws, a first actuator coupled to the first movable jaw, a second actuator coupled to the second movable jaw, a drive mechanism engageable with the first and second actuators and switching means having a first position which orients the drive mechanism to engage the first actuator and a second position which orients the drive mechanism to engage the second actuator for alternatively operating the first and second movable jaws.
Typically, the first and second movable jaws have a neutral position and the switching means is configured to force the drive mechanism to engage the first or second actuator only when the movable jaws are in the neutral position. The drive mechanism may be pivotable forward to engage the first actuator and pivotable rearward to engage the second actuator. The switching means may include a rocker member pivotable in one direction to urge the drive mechanism to pivot forward and pivotable in another direction to urge the drive mechanism to pivot rearward. The rocker member may include an arm and the switching means then further includes a first button and a compliant member between the first button and the arm to bias the arm of the rocker in a first direction independent of the position of the drive mechanism. The switching means may further include a pawl attached to the first button and a second compliant member disposed to bias the arm of the rocker in a second direction independent of the position of the drive mechanism.
The switchable actuator assembly of this invention typically includes a first actuator, a second actuator, a forward coupler attached to the proximal end of the first actuator and having a passage which receives the second actuator therethrough, a rearward coupler on the proximal end of the second actuator, a pivotable drive mechanism disposed over the forward and rearward couplers, and a switching mechanism engageable with the pivotable drive mechanism for pivoting the drive mechanism rearward to engage the rearward coupler and forward to engage the forward coupler. The switching mechanism includes a rocker member pivotable in a first direction to urge the drive mechanism to pivot rearward and pivotable in a second direction to urge the drive mechanism to pivot forward. The switching mechanism further includes an actuator compliantly coupled to the rocking member and operable independent of the position of the first and second actuators.
In the preferred embodiment, the rocker member includes a forward shelf which urges the drive mechanism to pivot rearward and a rearward shelf which urges the drive mechanism to pivot forward. Also in the preferred embodiment, the rocker member includes a forward locking member which holds the forward coupler stationary when the drive mechanism is engaged with the rearward coupler and a rearward locking member which holds the rearward coupler stationary when the drive mechanism is engaged with the forward coupler. The rocker member may include an arm and there may be a first spring extending between the first actuator and the arm to urge the arm rearward when the actuator is in a first position. The actuator may further include a pawl which urges the arm forward when the actuator is in a second position and a second spring which biases the actuator in the second position.
Typically, the actuator is a first button, the first position is depressed and the second position is released. The switching mechanism may further include a second button which locks the first button in the depressed position and which is itself depressible to release the first button.
In the preferred embodiment, there is an end effector assembly including a central fixed jaw with a grasping surface and a cutting surface, a first movable jaw including a grasping surface which engages the grasping surface of the central fixed jaw to grasp tissue therebetween as the first movable jaw is opened and closed. A second movable jaw includes a cutting surface which cooperates with the cutting surface of the central fixed jaw to cut tissue therebetween as the second movable jaw is opened and closed. A first actuator has a distal end coupled to the first movable jaw and reciprocates to open and close the first movable jaw. A second actuator has a distal end coupled to the second movable jaw and reciprocates to open and close the second movable jaw. There is also a handle assembly including the proximal ends of both the first and second actuators, a drive mechanism having a first position which engages the proximal end of the first actuator and a second position which engages the proximal end of the second actuator, and a movable trigger coupled with the drive mechanism to open and close the first movable jaw when the drive mechanism is engaged with the proximal end of the first actuator and to open and close the second movable jaw when the drive mechanism is engaged with the proximal end of the second actuator. The exemplary handle assembly further includes a switching mechanism coupled to the drive mechanism to switch it between the first and second positions.
The switching system, in one embodiment of this invention, features a pivotable drive mechanism translatable forward and rearward, a movable handle pivotable about a first pin and pivotably connected to the drive mechanism by a second pin, a rocker assembly pivotably disposed about the first pin and including a forward shelf which urges the drive mechanism to pivot in a first direction and a rearward shelf which urges the drive mechanism to pivot in a second direction. The rocker assembly may further include an arm depending therefrom. An actuator has first and second positions and includes a first compliant member (e.g., a spring) which urges the arm of the rocker assembly rearward when the actuator is in the first position to pivot the rocker assembly to engage the rearward shelf thereof with the drive mechanism. The actuator may further include a pawl which urges the arm of the rocker assembly forward when the actuator is in the second position to pivot the rocker assembly to engage the forward shelf thereof with the drive mechanism.
In one example, the actuator is a button depressible to the first position and releasable to the second position. A second compliant member is included, typically a spring, which biases the actuator in the second position.